Pressure-controlling device for pneumatic tires



.|. C. BRAKEIVIAN.

PRESSURE CONROLLlNG DEVICE FOR PNEUMATICTIRES.

APPLICTIN FILED AUG.I4, 1920.

Patented Jan. 10, 1922.

. pressure, and

rarasv `JESSE CLAIR BRAKEMAN, @El TORONTO, DNTAREO, CANADA.

PRESSURE-CONTROLLING DEVICE PNIEUNIATIC TIRES.

i Specification of Letters Patent.

Patented Jan. "l0, 1922.

Application led August 14, 1920. Serial No. 403,550.

To all whom t may concern.'

Be it known that I, JEssE CLAIR BRAKE- MAN, a citizen of the United States, and resident-of the City of Toronto, in the county of York and Province of Ontario, Dominion` of any usual or approved construction,

adapted for attachment to the air tube of the tire, and having therein a chamber pro'- vided with a valve closed relief port, and a movable member actuated by the pressure of the fluid within the air tube t0 automatically open the valve closed relief port and relieve the excesspressure.

For'an understanding of one means by which this object may be attained reference is vto be had to the following description and lto the accompanying drawings in whichq Fig. 1 is a vertical section of the pressure controlling device showing the Vparts in their normal position, y

Fig. 2 is a similar view to Fig. l, showing the parts actuated to relieve the excess Fig. 3 is an external view of the device.

Like characters of reference refer to like parts throughout the specilication and drawmors.

represents a tubular casing, preferably corresponding in structural detailswith the usual type of inllating stem with which air tubes of pneumatic tires are now equipped, in the interior of which is a chamber, a', for the fluid. Fitted into, or forming part of the head, a, of the casing is a tubular way, b, for the fluid. At or near the outer end of the tubular way is ahollow nipple, c, and at or near its inner end is a hollow nipple, d, these being respectively the inlet and relief ports for the chamber, a', and in the opposed faces of the nipples o and d are valve seats, c', d', respectively.`

Engaging the valve seat o 1s a valve e,

. providedr with valvel` pine, extendin through the nippley o, and slightly' beyon y the outer end ofthe tubularway l). f

Engaging the valve seat, 0I', is a valve, f, provided with a valve pin, f', extending through the nipple,d, and beyond the inner end ofthe tubular way,

The length of the valve pin, f, is regulated tothe predetermined pressure at which the valve j", will be moved from its seat. For

example, ifthe valve is to open at a pressure ofone hundred `pounds per square inch, the valve pin may be of a length to extend one sixteenth of an inch beyond the inner yend of the tubular way, o. lf it is to open at a pressure of ninety-live pounds per square inch the valve pin will be of a length to extend two sixteenths of an inch beyond the inner end ofthe tubular way, and so' on,.the length-0f the valve lpin 'increasing one sixteenth of an inch'for each five pounds of decrease of pressure. `These measurements are given only as an example of the construction and operation of the device andy it is to be understood that they may be varied within a wide range;

`Within the tubular way,V Z), is a coiled spring, g, bearing against the valves e and f, and normally holding` them on the valve seats, c', d', respectively.

F ormed'through the wall of the tubular way, Z), are orifices, z., establishing a passagefor the fluid from the inlet port through f the tubular way to thechamber, a', .of the casing a, when the fluid is being forced into the tire. and from the chamber a', through the tubular way to the relief port when the valve 7 is lifted from its seat to relieve the pressure within thetire.

Nithin the casing a, is a cylindrical wall, e', extending from the base of the casing to the inner end of the vtubularway b, and of less diameter than and suitably separated from the inner surface of the casing to form the chamber a', through which the fluid passes to and from the tubular way, the

cylindrical wall, z', being preferably arranged 'eccentrically to the inner circumference of the casing, and in airtightcontact with it where their surfaces meet.

Formed through the contacting part of the surfacesof the casing and cylindrical wall is a slot, y', and on the outer surface of the casing along the sides of the slot are graduations, j', for indicating the pressure ofthe fluid. 

